1. Field of the Invention
The present invention generally relates to a light source device. More particularly, the present invention relates to a light source device having a molding lens.
2. Description of Related Art
In the recent years, along with the progression of semiconductor technology, light emitting diode (LED) is able to emit light beam having high luminous intensity, and the luminous efficiency of the LED is constantly improved. Compared to some conventional light sources, the LED light source has the advantages of energy efficient, small size and long life expectancy. Therefore, the conventional light sources are gradually replaced with the LED light source, and the LED light source is widely applied in the field of lighting, such as car headlights, street lamps, desk lamps, etc.
The LED light sources used for illumination generally has an angle of half maximum power that is approximately 120 degrees, and the luminous intensity of the LED at the forward direction substantially perpendicular to the light-emitting surface is higher while that at the oblique direction oblique to the forward direction is weaker. In other words, the light emitted by the LED has a Lambertian distribution. Therefore, if the LED light source is directly applied in a conventional light bulb without any modification, the light emission angle of the light bulb having the LED light source would be restricted, and particularly, the light intensity at a side oblique to the light-emitting side of the light source is even weaker. In order to increase the light emission angle of the lamp, some LED light bulbs are incorporated with a lamp housing having the scattering effect. By such lamp housing, the light intensity in the direction oblique to the light-emitting side of the LED light bulb may be increased. However, it is still not enough to meet the requirement of the omni-directional lighting.